1. Field of the Invention
The present invention relates to a method and apparatus for controlling a data storage system, and more particularly, to a method of and apparatus for performing a defect scan on a data storage system by determining design parameters based on the system's channel characteristics.
2. Description of the Related Art
A hard disc drive is an auxiliary memory device for computers that writes or reads data with respect to a disc using a magnetic head. As the capacity and integration density of a hard disc drive increases and its size decreases, the bits per inch (BPI) and tracks per inch (TPI) of the hard disc increase. BPI and TPI represent the writing density in a disc rotation direction and track thickness per inch of a disc, respectively. Thus, it is required to more precisely and rapidly control the position of the head.
A conventional hard disc drive is generally manufactured to include at least one disc and at least one head. That is, a hard disc drive includes a multi-channel disc and a head.
A surface of a disc is coated with a magnetic material. If a magnetic layer is not evenly applied onto the surface of the disc or the inside of the hard disc drive is contaminated with dust during assembling of the hard disc drive, the disc may contain a defect. The defect prevents the disc from being appropriately magnetized, and therefore information cannot be written to the disc or data already written on the disc is erased.
Conventionally, when manufacturing a hard disc drive, the presence of defects on a disc is determined by performing a defect scan thereon and an area of the disc in which a defect occurs is slipped so that a user cannot use the area, thereby minimizing loss of information. In the conventional method, the defect scan is carried out using design parameters, such as the length of an error correction code (ECC) which are determined to be the same for all disc channels regardless of channel characteristics. However, most hard disc drives have multi-channels and the characteristics of the channels may be different from each other depending upon the state of a disc, the types of devices installed in a hard disc drive, and the state of the devices that are assembled together in the hard disc drive. Although design parameters are set to be the same irrespective of channel characteristics, it is still possible to obtain different results when performing a defect scan with respect to the same-sized defects in different channels, thereby decreasing the quality of a hard disc.